The origin of inflammation in the ESRD population is unclear, although the HD session per se has been implicated. Korevaar et al studied the effect of the HD session on CRP level and mortality in 186 pts. (7) Thirty-eight % of patients had a CRP level below detection (<3 mg/L), and in those patients with detectable CRP levels pre-HD 37% had no increase with HD, and 25% of patients had an increase (mean +2.3 (0.6-9.2)) in CRP level (adjusted for change in blood volume) during HD. There was no difference in pre-HD CRP level between the latter 2 groups. A lower 2 yr survival was observed in the group in which CRP increased during HD, (44 vs. 66%, p=0.09). After adjusting for nutritional factors, age, comorbidity and primary kidney disease, a rise of 1 mg/dl in CRP during a HD session, was associated with an increase in mortality risk of 9% (Adjusted hazard ratio 1.09, 95%CI=1.09-1.16) Independent predictors of high CRP levels during HD include patient age (β=0.07, p=0.05), pre-HD CRP (β=0.95, p<0.01), 2 needle dialysis (β=2.39, p=0.05, and cholesterol ((β= -0.92, p=0.04).